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-rw-r--r--net/dccp/ccids/Kconfig29
-rw-r--r--net/dccp/ccids/Makefile5
-rw-r--r--net/dccp/ccids/ccid3.c1221
-rw-r--r--net/dccp/ccids/ccid3.h137
-rw-r--r--net/dccp/ccids/lib/Makefile3
-rw-r--r--net/dccp/ccids/lib/loss_interval.c144
-rw-r--r--net/dccp/ccids/lib/loss_interval.h61
-rw-r--r--net/dccp/ccids/lib/packet_history.c398
-rw-r--r--net/dccp/ccids/lib/packet_history.h199
-rw-r--r--net/dccp/ccids/lib/tfrc.h22
-rw-r--r--net/dccp/ccids/lib/tfrc_equation.c644
11 files changed, 2863 insertions, 0 deletions
diff --git a/net/dccp/ccids/Kconfig b/net/dccp/ccids/Kconfig
new file mode 100644
index 00000000000..7684d83946a
--- /dev/null
+++ b/net/dccp/ccids/Kconfig
@@ -0,0 +1,29 @@
+menu "DCCP CCIDs Configuration (EXPERIMENTAL)"
+ depends on IP_DCCP && EXPERIMENTAL
+
+config IP_DCCP_CCID3
+ tristate "CCID3 (TFRC) (EXPERIMENTAL)"
+ depends on IP_DCCP
+ ---help---
+ CCID 3 denotes TCP-Friendly Rate Control (TFRC), an equation-based
+ rate-controlled congestion control mechanism. TFRC is designed to
+ be reasonably fair when competing for bandwidth with TCP-like flows,
+ where a flow is "reasonably fair" if its sending rate is generally
+ within a factor of two of the sending rate of a TCP flow under the
+ same conditions. However, TFRC has a much lower variation of
+ throughput over time compared with TCP, which makes CCID 3 more
+ suitable than CCID 2 for applications such streaming media where a
+ relatively smooth sending rate is of importance.
+
+ CCID 3 is further described in [CCID 3 PROFILE]. The TFRC
+ congestion control algorithms were initially described in RFC 3448.
+
+ This text was extracted from draft-ietf-dccp-spec-11.txt.
+
+ If in doubt, say M.
+
+config IP_DCCP_TFRC_LIB
+ depends on IP_DCCP_CCID3
+ def_tristate IP_DCCP_CCID3
+
+endmenu
diff --git a/net/dccp/ccids/Makefile b/net/dccp/ccids/Makefile
new file mode 100644
index 00000000000..956f79f5074
--- /dev/null
+++ b/net/dccp/ccids/Makefile
@@ -0,0 +1,5 @@
+obj-$(CONFIG_IP_DCCP_CCID3) += dccp_ccid3.o
+
+dccp_ccid3-y := ccid3.o
+
+obj-y += lib/
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
new file mode 100644
index 00000000000..7bf3b3a91e9
--- /dev/null
+++ b/net/dccp/ccids/ccid3.c
@@ -0,0 +1,1221 @@
+/*
+ * net/dccp/ccids/ccid3.c
+ *
+ * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
+ * Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
+ *
+ * An implementation of the DCCP protocol
+ *
+ * This code has been developed by the University of Waikato WAND
+ * research group. For further information please see http://www.wand.net.nz/
+ *
+ * This code also uses code from Lulea University, rereleased as GPL by its
+ * authors:
+ * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
+ *
+ * Changes to meet Linux coding standards, to make it meet latest ccid3 draft
+ * and to make it work as a loadable module in the DCCP stack written by
+ * Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
+ *
+ * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/config.h>
+#include "../ccid.h"
+#include "../dccp.h"
+#include "lib/packet_history.h"
+#include "lib/loss_interval.h"
+#include "lib/tfrc.h"
+#include "ccid3.h"
+
+/*
+ * Reason for maths with 10 here is to avoid 32 bit overflow when a is big.
+ */
+static inline u32 usecs_div(const u32 a, const u32 b)
+{
+ const u32 tmp = a * (USEC_PER_SEC / 10);
+ return b > 20 ? tmp / (b / 10) : tmp;
+}
+
+static int ccid3_debug;
+
+#ifdef CCID3_DEBUG
+#define ccid3_pr_debug(format, a...) \
+ do { if (ccid3_debug) \
+ printk(KERN_DEBUG "%s: " format, __FUNCTION__, ##a); \
+ } while (0)
+#else
+#define ccid3_pr_debug(format, a...)
+#endif
+
+static struct dccp_tx_hist *ccid3_tx_hist;
+static struct dccp_rx_hist *ccid3_rx_hist;
+static struct dccp_li_hist *ccid3_li_hist;
+
+static int ccid3_init(struct sock *sk)
+{
+ ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
+ return 0;
+}
+
+static void ccid3_exit(struct sock *sk)
+{
+ ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
+}
+
+/* TFRC sender states */
+enum ccid3_hc_tx_states {
+ TFRC_SSTATE_NO_SENT = 1,
+ TFRC_SSTATE_NO_FBACK,
+ TFRC_SSTATE_FBACK,
+ TFRC_SSTATE_TERM,
+};
+
+#ifdef CCID3_DEBUG
+static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state)
+{
+ static char *ccid3_state_names[] = {
+ [TFRC_SSTATE_NO_SENT] = "NO_SENT",
+ [TFRC_SSTATE_NO_FBACK] = "NO_FBACK",
+ [TFRC_SSTATE_FBACK] = "FBACK",
+ [TFRC_SSTATE_TERM] = "TERM",
+ };
+
+ return ccid3_state_names[state];
+}
+#endif
+
+static inline void ccid3_hc_tx_set_state(struct sock *sk,
+ enum ccid3_hc_tx_states state)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
+ enum ccid3_hc_tx_states oldstate = hctx->ccid3hctx_state;
+
+ ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
+ dccp_role(sk), sk, ccid3_tx_state_name(oldstate),
+ ccid3_tx_state_name(state));
+ WARN_ON(state == oldstate);
+ hctx->ccid3hctx_state = state;
+}
+
+/* Calculate new t_ipi (inter packet interval) by t_ipi = s / X_inst */
+static inline void ccid3_calc_new_t_ipi(struct ccid3_hc_tx_sock *hctx)
+{
+ /*
+ * If no feedback spec says t_ipi is 1 second (set elsewhere and then
+ * doubles after every no feedback timer (separate function)
+ */
+ if (hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK)
+ hctx->ccid3hctx_t_ipi = usecs_div(hctx->ccid3hctx_s,
+ hctx->ccid3hctx_x);
+}
+
+/* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */
+static inline void ccid3_calc_new_delta(struct ccid3_hc_tx_sock *hctx)
+{
+ hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2,
+ TFRC_OPSYS_HALF_TIME_GRAN);
+}
+
+/*
+ * Update X by
+ * If (p > 0)
+ * x_calc = calcX(s, R, p);
+ * X = max(min(X_calc, 2 * X_recv), s / t_mbi);
+ * Else
+ * If (now - tld >= R)
+ * X = max(min(2 * X, 2 * X_recv), s / R);
+ * tld = now;
+ */
+static void ccid3_hc_tx_update_x(struct sock *sk)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
+
+ /* To avoid large error in calcX */
+ if (hctx->ccid3hctx_p >= TFRC_SMALLEST_P) {
+ hctx->ccid3hctx_x_calc = tfrc_calc_x(hctx->ccid3hctx_s,
+ hctx->ccid3hctx_rtt,
+ hctx->ccid3hctx_p);
+ hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_calc,
+ 2 * hctx->ccid3hctx_x_recv),
+ (hctx->ccid3hctx_s /
+ TFRC_MAX_BACK_OFF_TIME));
+ } else {
+ struct timeval now;
+
+ do_gettimeofday(&now);
+ if (timeval_delta(&now, &hctx->ccid3hctx_t_ld) >=
+ hctx->ccid3hctx_rtt) {
+ hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_recv,
+ hctx->ccid3hctx_x) * 2,
+ usecs_div(hctx->ccid3hctx_s,
+ hctx->ccid3hctx_rtt));
+ hctx->ccid3hctx_t_ld = now;
+ }
+ }
+}
+
+static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
+{
+ struct sock *sk = (struct sock *)data;
+ struct dccp_sock *dp = dccp_sk(sk);
+ unsigned long next_tmout = 0;
+ struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
+
+ bh_lock_sock(sk);
+ if (sock_owned_by_user(sk)) {
+ /* Try again later. */
+ /* XXX: set some sensible MIB */
+ sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
+ jiffies + HZ / 5);
+ goto out;
+ }
+
+ ccid3_pr_debug("%s, sk=%p, state=%s\n", dccp_role(sk), sk,
+ ccid3_tx_state_name(hctx->ccid3hctx_state));
+
+ switch (hctx->ccid3hctx_state) {
+ case TFRC_SSTATE_TERM:
+ goto out;
+ case TFRC_SSTATE_NO_FBACK:
+ /* Halve send rate */
+ hctx->ccid3hctx_x /= 2;
+ if (hctx->ccid3hctx_x < (hctx->ccid3hctx_s /
+ TFRC_MAX_BACK_OFF_TIME))
+ hctx->ccid3hctx_x = (hctx->ccid3hctx_s /
+ TFRC_MAX_BACK_OFF_TIME);
+
+ ccid3_pr_debug("%s, sk=%p, state=%s, updated tx rate to %d "
+ "bytes/s\n",
+ dccp_role(sk), sk,
+ ccid3_tx_state_name(hctx->ccid3hctx_state),
+ hctx->ccid3hctx_x);
+ next_tmout = max_t(u32, 2 * usecs_div(hctx->ccid3hctx_s,
+ hctx->ccid3hctx_x),
+ TFRC_INITIAL_TIMEOUT);
+ /*
+ * FIXME - not sure above calculation is correct. See section
+ * 5 of CCID3 11 should adjust tx_t_ipi and double that to
+ * achieve it really
+ */
+ break;
+ case TFRC_SSTATE_FBACK:
+ /*
+ * Check if IDLE since last timeout and recv rate is less than
+ * 4 packets per RTT
+ */
+ if (!hctx->ccid3hctx_idle ||
+ (hctx->ccid3hctx_x_recv >=
+ 4 * usecs_div(hctx->ccid3hctx_s, hctx->ccid3hctx_rtt))) {
+ ccid3_pr_debug("%s, sk=%p, state=%s, not idle\n",
+ dccp_role(sk), sk,
+ ccid3_tx_state_name(hctx->ccid3hctx_state));
+ /* Halve sending rate */
+
+ /* If (X_calc > 2 * X_recv)
+ * X_recv = max(X_recv / 2, s / (2 * t_mbi));
+ * Else
+ * X_recv = X_calc / 4;
+ */
+ BUG_ON(hctx->ccid3hctx_p >= TFRC_SMALLEST_P &&
+ hctx->ccid3hctx_x_calc == 0);
+
+ /* check also if p is zero -> x_calc is infinity? */
+ if (hctx->ccid3hctx_p < TFRC_SMALLEST_P ||
+ hctx->ccid3hctx_x_calc > 2 * hctx->ccid3hctx_x_recv)
+ hctx->ccid3hctx_x_recv = max_t(u32, hctx->ccid3hctx_x_recv / 2,
+ hctx->ccid3hctx_s / (2 * TFRC_MAX_BACK_OFF_TIME));
+ else
+ hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc / 4;
+
+ /* Update sending rate */
+ ccid3_hc_tx_update_x(sk);
+ }
+ /*
+ * Schedule no feedback timer to expire in
+ * max(4 * R, 2 * s / X)
+ */
+ next_tmout = max_t(u32, hctx->ccid3hctx_t_rto,
+ 2 * usecs_div(hctx->ccid3hctx_s,
+ hctx->ccid3hctx_x));
+ break;
+ default:
+ printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
+ __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
+ dump_stack();
+ goto out;
+ }
+
+ sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
+ jiffies + max_t(u32, 1, usecs_to_jiffies(next_tmout)));
+ hctx->ccid3hctx_idle = 1;
+out:
+ bh_unlock_sock(sk);
+ sock_put(sk);
+}
+
+static int ccid3_hc_tx_send_packet(struct sock *sk,
+ struct sk_buff *skb, int len)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
+ struct dccp_tx_hist_entry *new_packet;
+ struct timeval now;
+ long delay;
+ int rc = -ENOTCONN;
+
+ /* Check if pure ACK or Terminating*/
+
+ /*
+ * XXX: We only call this function for DATA and DATAACK, on, these
+ * packets can have zero length, but why the comment about "pure ACK"?
+ */
+ if (hctx == NULL || len == 0 ||
+ hctx->ccid3hctx_state == TFRC_SSTATE_TERM)
+ goto out;
+
+ /* See if last packet allocated was not sent */
+ new_packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
+ if (new_packet == NULL || new_packet->dccphtx_sent) {
+ new_packet = dccp_tx_hist_entry_new(ccid3_tx_hist,
+ SLAB_ATOMIC);
+
+ rc = -ENOBUFS;
+ if (new_packet == NULL) {
+ ccid3_pr_debug("%s, sk=%p, not enough mem to add "
+ "to history, send refused\n",
+ dccp_role(sk), sk);
+ goto out;
+ }
+
+ dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, new_packet);
+ }
+
+ do_gettimeofday(&now);
+
+ switch (hctx->ccid3hctx_state) {
+ case TFRC_SSTATE_NO_SENT:
+ ccid3_pr_debug("%s, sk=%p, first packet(%llu)\n",
+ dccp_role(sk), sk, dp->dccps_gss);
+
+ hctx->ccid3hctx_no_feedback_timer.function = ccid3_hc_tx_no_feedback_timer;
+ hctx->ccid3hctx_no_feedback_timer.data = (unsigned long)sk;
+ sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
+ jiffies + usecs_to_jiffies(TFRC_INITIAL_TIMEOUT));
+ hctx->ccid3hctx_last_win_count = 0;
+ hctx->ccid3hctx_t_last_win_count = now;
+ ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK);
+ hctx->ccid3hctx_t_ipi = TFRC_INITIAL_TIMEOUT;
+
+ /* Set nominal send time for initial packet */
+ hctx->ccid3hctx_t_nom = now;
+ timeval_add_usecs(&hctx->ccid3hctx_t_nom,
+ hctx->ccid3hctx_t_ipi);
+ ccid3_calc_new_delta(hctx);
+ rc = 0;
+ break;
+ case TFRC_SSTATE_NO_FBACK:
+ case TFRC_SSTATE_FBACK:
+ delay = (timeval_delta(&now, &hctx->ccid3hctx_t_nom) -
+ hctx->ccid3hctx_delta);
+ ccid3_pr_debug("send_packet delay=%ld\n", delay);
+ delay /= -1000;
+ /* divide by -1000 is to convert to ms and get sign right */
+ rc = delay > 0 ? delay : 0;
+ break;
+ default:
+ printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
+ __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
+ dump_stack();
+ rc = -EINVAL;
+ break;
+ }
+
+ /* Can we send? if so add options and add to packet history */
+ if (rc == 0)
+ new_packet->dccphtx_ccval =
+ DCCP_SKB_CB(skb)->dccpd_ccval =
+ hctx->ccid3hctx_last_win_count;
+out:
+ return rc;
+}
+
+static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, int len)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
+ struct timeval now;
+
+ BUG_ON(hctx == NULL);
+
+ if (hctx->ccid3hctx_state == TFRC_SSTATE_TERM) {
+ ccid3_pr_debug("%s, sk=%p, while state is TFRC_SSTATE_TERM!\n",
+ dccp_role(sk), sk);
+ return;
+ }
+
+ do_gettimeofday(&now);
+
+ /* check if we have sent a data packet */
+ if (len > 0) {
+ unsigned long quarter_rtt;
+ struct dccp_tx_hist_entry *packet;
+
+ packet = dccp_tx_hist_head(&hctx->ccid3hctx_hist);
+ if (packet == NULL) {
+ printk(KERN_CRIT "%s: packet doesn't exists in "
+ "history!\n", __FUNCTION__);
+ return;
+ }
+ if (packet->dccphtx_sent) {
+ printk(KERN_CRIT "%s: no unsent packet in history!\n",
+ __FUNCTION__);
+ return;
+ }
+ packet->dccphtx_tstamp = now;
+ packet->dccphtx_seqno = dp->dccps_gss;
+ /*
+ * Check if win_count have changed
+ * Algorithm in "8.1. Window Counter Valuer" in
+ * draft-ietf-dccp-ccid3-11.txt
+ */
+ quarter_rtt = timeval_delta(&now, &hctx->ccid3hctx_t_last_win_count);
+ if (likely(hctx->ccid3hctx_rtt > 8))
+ quarter_rtt /= hctx->ccid3hctx_rtt / 4;
+
+ if (quarter_rtt > 0) {
+ hctx->ccid3hctx_t_last_win_count = now;
+ hctx->ccid3hctx_last_win_count = (hctx->ccid3hctx_last_win_count +
+ min_t(unsigned long, quarter_rtt, 5)) % 16;
+ ccid3_pr_debug("%s, sk=%p, window changed from "
+ "%u to %u!\n",
+ dccp_role(sk), sk,
+ packet->dccphtx_ccval,
+ hctx->ccid3hctx_last_win_count);
+ }
+
+ hctx->ccid3hctx_idle = 0;
+ packet->dccphtx_rtt = hctx->ccid3hctx_rtt;
+ packet->dccphtx_sent = 1;
+ } else
+ ccid3_pr_debug("%s, sk=%p, seqno=%llu NOT inserted!\n",
+ dccp_role(sk), sk, dp->dccps_gss);
+
+ switch (hctx->ccid3hctx_state) {
+ case TFRC_SSTATE_NO_SENT:
+ /* if first wasn't pure ack */
+ if (len != 0)
+ printk(KERN_CRIT "%s: %s, First packet sent is noted "
+ "as a data packet\n",
+ __FUNCTION__, dccp_role(sk));
+ return;
+ case TFRC_SSTATE_NO_FBACK:
+ case TFRC_SSTATE_FBACK:
+ if (len > 0) {
+ hctx->ccid3hctx_t_nom = now;
+ ccid3_calc_new_t_ipi(hctx);
+ ccid3_calc_new_delta(hctx);
+ timeval_add_usecs(&hctx->ccid3hctx_t_nom,
+ hctx->ccid3hctx_t_ipi);
+ }
+ break;
+ default:
+ printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
+ __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
+ dump_stack();
+ break;
+ }
+}
+
+static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
+ struct ccid3_options_received *opt_recv;
+ struct dccp_tx_hist_entry *packet;
+ unsigned long next_tmout;
+ u32 t_elapsed;
+ u32 pinv;
+ u32 x_recv;
+ u32 r_sample;
+
+ if (hctx == NULL)
+ return;
+
+ if (hctx->ccid3hctx_state == TFRC_SSTATE_TERM) {
+ ccid3_pr_debug("%s, sk=%p, received a packet when "
+ "terminating!\n", dccp_role(sk), sk);
+ return;
+ }
+
+ /* we are only interested in ACKs */
+ if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK ||
+ DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK))
+ return;
+
+ opt_recv = &hctx->ccid3hctx_options_received;
+
+ t_elapsed = dp->dccps_options_received.dccpor_elapsed_time;
+ x_recv = opt_recv->ccid3or_receive_rate;
+ pinv = opt_recv->ccid3or_loss_event_rate;
+
+ switch (hctx->ccid3hctx_state) {
+ case TFRC_SSTATE_NO_SENT:
+ /* FIXME: what to do here? */
+ return;
+ case TFRC_SSTATE_NO_FBACK:
+ case TFRC_SSTATE_FBACK:
+ /* Calculate new round trip sample by
+ * R_sample = (now - t_recvdata) - t_delay */
+ /* get t_recvdata from history */
+ packet = dccp_tx_hist_find_entry(&hctx->ccid3hctx_hist,
+ DCCP_SKB_CB(skb)->dccpd_ack_seq);
+ if (packet == NULL) {
+ ccid3_pr_debug("%s, sk=%p, seqno %llu(%s) does't "
+ "exist in history!\n",
+ dccp_role(sk), sk,
+ DCCP_SKB_CB(skb)->dccpd_ack_seq,
+ dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));
+ return;
+ }
+
+ /* Update RTT */
+ r_sample = timeval_now_delta(&packet->dccphtx_tstamp);
+ /* FIXME: */
+ // r_sample -= usecs_to_jiffies(t_elapsed * 10);
+
+ /* Update RTT estimate by
+ * If (No feedback recv)
+ * R = R_sample;
+ * Else
+ * R = q * R + (1 - q) * R_sample;
+ *
+ * q is a constant, RFC 3448 recomments 0.9
+ */
+ if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) {
+ ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK);
+ hctx->ccid3hctx_rtt = r_sample;
+ } else
+ hctx->ccid3hctx_rtt = (hctx->ccid3hctx_rtt * 9) / 10 +
+ r_sample / 10;
+
+ ccid3_pr_debug("%s, sk=%p, New RTT estimate=%uus, "
+ "r_sample=%us\n", dccp_role(sk), sk,
+ hctx->ccid3hctx_rtt, r_sample);
+
+ /* Update timeout interval */
+ hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt,
+ USEC_PER_SEC);
+
+ /* Update receive rate */
+ hctx->ccid3hctx_x_recv = x_recv;/* X_recv in bytes per sec */
+
+ /* Update loss event rate */
+ if (pinv == ~0 || pinv == 0)
+ hctx->ccid3hctx_p = 0;
+ else {
+ hctx->ccid3hctx_p = 1000000 / pinv;
+
+ if (hctx->ccid3hctx_p < TFRC_SMALLEST_P) {
+ hctx->ccid3hctx_p = TFRC_SMALLEST_P;
+ ccid3_pr_debug("%s, sk=%p, Smallest p used!\n",
+ dccp_role(sk), sk);
+ }
+ }
+
+ /* unschedule no feedback timer */
+ sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
+
+ /* Update sending rate */
+ ccid3_hc_tx_update_x(sk);
+
+ /* Update next send time */
+ timeval_sub_usecs(&hctx->ccid3hctx_t_nom,
+ hctx->ccid3hctx_t_ipi);
+ ccid3_calc_new_t_ipi(hctx);
+ timeval_add_usecs(&hctx->ccid3hctx_t_nom,
+ hctx->ccid3hctx_t_ipi);
+ ccid3_calc_new_delta(hctx);
+
+ /* remove all packets older than the one acked from history */
+ dccp_tx_hist_purge_older(ccid3_tx_hist,
+ &hctx->ccid3hctx_hist, packet);
+ /*
+ * As we have calculated new ipi, delta, t_nom it is possible that
+ * we now can send a packet, so wake up dccp_wait_for_ccids.
+ */
+ sk->sk_write_space(sk);
+
+ /*
+ * Schedule no feedback timer to expire in
+ * max(4 * R, 2 * s / X)
+ */
+ next_tmout = max(hctx->ccid3hctx_t_rto,
+ 2 * usecs_div(hctx->ccid3hctx_s,
+ hctx->ccid3hctx_x));
+
+ ccid3_pr_debug("%s, sk=%p, Scheduled no feedback timer to "
+ "expire in %lu jiffies (%luus)\n",
+ dccp_role(sk), sk,
+ usecs_to_jiffies(next_tmout), next_tmout);
+
+ sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer,
+ jiffies + max_t(u32, 1, usecs_to_jiffies(next_tmout)));
+
+ /* set idle flag */
+ hctx->ccid3hctx_idle = 1;
+ break;
+ default:
+ printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
+ __FUNCTION__, dccp_role(sk), sk, hctx->ccid3hctx_state);
+ dump_stack();
+ break;
+ }
+}
+
+static void ccid3_hc_tx_insert_options(struct sock *sk, struct sk_buff *skb)
+{
+ const struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
+
+ if (hctx == NULL || !(sk->sk_state == DCCP_OPEN ||
+ sk->sk_state == DCCP_PARTOPEN))
+ return;
+
+ DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count;
+}
+
+static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
+ unsigned char len, u16 idx,
+ unsigned char *value)
+{
+ int rc = 0;
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
+ struct ccid3_options_received *opt_recv;
+
+ if (hctx == NULL)
+ return 0;
+
+ opt_recv = &hctx->ccid3hctx_options_received;
+
+ if (opt_recv->ccid3or_seqno != dp->dccps_gsr) {
+ opt_recv->ccid3or_seqno = dp->dccps_gsr;
+ opt_recv->ccid3or_loss_event_rate = ~0;
+ opt_recv->ccid3or_loss_intervals_idx = 0;
+ opt_recv->ccid3or_loss_intervals_len = 0;
+ opt_recv->ccid3or_receive_rate = 0;
+ }
+
+ switch (option) {
+ case TFRC_OPT_LOSS_EVENT_RATE:
+ if (len != 4) {
+ ccid3_pr_debug("%s, sk=%p, invalid len for "
+ "TFRC_OPT_LOSS_EVENT_RATE\n",
+ dccp_role(sk), sk);
+ rc = -EINVAL;
+ } else {
+ opt_recv->ccid3or_loss_event_rate = ntohl(*(u32 *)value);
+ ccid3_pr_debug("%s, sk=%p, LOSS_EVENT_RATE=%u\n",
+ dccp_role(sk), sk,
+ opt_recv->ccid3or_loss_event_rate);
+ }
+ break;
+ case TFRC_OPT_LOSS_INTERVALS:
+ opt_recv->ccid3or_loss_intervals_idx = idx;
+ opt_recv->ccid3or_loss_intervals_len = len;
+ ccid3_pr_debug("%s, sk=%p, LOSS_INTERVALS=(%u, %u)\n",
+ dccp_role(sk), sk,
+ opt_recv->ccid3or_loss_intervals_idx,
+ opt_recv->ccid3or_loss_intervals_len);
+ break;
+ case TFRC_OPT_RECEIVE_RATE:
+ if (len != 4) {
+ ccid3_pr_debug("%s, sk=%p, invalid len for "
+ "TFRC_OPT_RECEIVE_RATE\n",
+ dccp_role(sk), sk);
+ rc = -EINVAL;
+ } else {
+ opt_recv->ccid3or_receive_rate = ntohl(*(u32 *)value);
+ ccid3_pr_debug("%s, sk=%p, RECEIVE_RATE=%u\n",
+ dccp_role(sk), sk,
+ opt_recv->ccid3or_receive_rate);
+ }
+ break;
+ }
+
+ return rc;
+}
+
+static int ccid3_hc_tx_init(struct sock *sk)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid3_hc_tx_sock *hctx;
+
+ ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
+
+ hctx = dp->dccps_hc_tx_ccid_private = kmalloc(sizeof(*hctx),
+ gfp_any());
+ if (hctx == NULL)
+ return -ENOMEM;
+
+ memset(hctx, 0, sizeof(*hctx));
+
+ if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
+ dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
+ hctx->ccid3hctx_s = dp->dccps_packet_size;
+ else
+ hctx->ccid3hctx_s = TFRC_STD_PACKET_SIZE;
+
+ /* Set transmission rate to 1 packet per second */
+ hctx->ccid3hctx_x = hctx->ccid3hctx_s;
+ hctx->ccid3hctx_t_rto = USEC_PER_SEC;
+ hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT;
+ INIT_LIST_HEAD(&hctx->ccid3hctx_hist);
+ init_timer(&hctx->ccid3hctx_no_feedback_timer);
+
+ return 0;
+}
+
+static void ccid3_hc_tx_exit(struct sock *sk)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
+
+ ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
+ BUG_ON(hctx == NULL);
+
+ ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM);
+ sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer);
+
+ /* Empty packet history */
+ dccp_tx_hist_purge(ccid3_tx_hist, &hctx->ccid3hctx_hist);
+
+ kfree(dp->dccps_hc_tx_ccid_private);
+ dp->dccps_hc_tx_ccid_private = NULL;
+}
+
+/*
+ * RX Half Connection methods
+ */
+
+/* TFRC receiver states */
+enum ccid3_hc_rx_states {
+ TFRC_RSTATE_NO_DATA = 1,
+ TFRC_RSTATE_DATA,
+ TFRC_RSTATE_TERM = 127,
+};
+
+#ifdef CCID3_DEBUG
+static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state)
+{
+ static char *ccid3_rx_state_names[] = {
+ [TFRC_RSTATE_NO_DATA] = "NO_DATA",
+ [TFRC_RSTATE_DATA] = "DATA",
+ [TFRC_RSTATE_TERM] = "TERM",
+ };
+
+ return ccid3_rx_state_names[state];
+}
+#endif
+
+static inline void ccid3_hc_rx_set_state(struct sock *sk,
+ enum ccid3_hc_rx_states state)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
+ enum ccid3_hc_rx_states oldstate = hcrx->ccid3hcrx_state;
+
+ ccid3_pr_debug("%s(%p) %-8.8s -> %s\n",
+ dccp_role(sk), sk, ccid3_rx_state_name(oldstate),
+ ccid3_rx_state_name(state));
+ WARN_ON(state == oldstate);
+ hcrx->ccid3hcrx_state = state;
+}
+
+static void ccid3_hc_rx_send_feedback(struct sock *sk)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
+ struct dccp_rx_hist_entry *packet;
+ struct timeval now;
+
+ ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
+
+ do_gettimeofday(&now);
+
+ switch (hcrx->ccid3hcrx_state) {
+ case TFRC_RSTATE_NO_DATA:
+ hcrx->ccid3hcrx_x_recv = 0;
+ break;
+ case TFRC_RSTATE_DATA: {
+ const u32 delta = timeval_delta(&now,
+ &hcrx->ccid3hcrx_tstamp_last_feedback);
+
+ hcrx->ccid3hcrx_x_recv = (hcrx->ccid3hcrx_bytes_recv *
+ USEC_PER_SEC);
+ if (likely(delta > 1))
+ hcrx->ccid3hcrx_x_recv /= delta;
+ }
+ break;
+ default:
+ printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
+ __FUNCTION__, dccp_role(sk), sk, hcrx->ccid3hcrx_state);
+ dump_stack();
+ return;
+ }
+
+ packet = dccp_rx_hist_find_data_packet(&hcrx->ccid3hcrx_hist);
+ if (packet == NULL) {
+ printk(KERN_CRIT "%s: %s, sk=%p, no data packet in history!\n",
+ __FUNCTION__, dccp_role(sk), sk);
+ dump_stack();
+ return;
+ }
+
+ hcrx->ccid3hcrx_tstamp_last_feedback = now;
+ hcrx->ccid3hcrx_last_counter = packet->dccphrx_ccval;
+ hcrx->ccid3hcrx_seqno_last_counter = packet->dccphrx_seqno;
+ hcrx->ccid3hcrx_bytes_recv = 0;
+
+ /* Convert to multiples of 10us */
+ hcrx->ccid3hcrx_elapsed_time =
+ timeval_delta(&now, &packet->dccphrx_tstamp) / 10;
+ if (hcrx->ccid3hcrx_p == 0)
+ hcrx->ccid3hcrx_pinv = ~0;
+ else
+ hcrx->ccid3hcrx_pinv = 1000000 / hcrx->ccid3hcrx_p;
+ dccp_send_ack(sk);
+}
+
+static void ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb)
+{
+ const struct dccp_sock *dp = dccp_sk(sk);
+ u32 x_recv, pinv;
+ struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
+
+ if (hcrx == NULL || !(sk->sk_state == DCCP_OPEN ||
+ sk->sk_state == DCCP_PARTOPEN))
+ return;
+
+ DCCP_SKB_CB(skb)->dccpd_ccval = hcrx->ccid3hcrx_last_counter;
+
+ if (dccp_packet_without_ack(skb))
+ return;
+
+ if (hcrx->ccid3hcrx_elapsed_time != 0)
+ dccp_insert_option_elapsed_time(sk, skb,
+ hcrx->ccid3hcrx_elapsed_time);
+ dccp_insert_option_timestamp(sk, skb);
+ x_recv = htonl(hcrx->ccid3hcrx_x_recv);
+ pinv = htonl(hcrx->ccid3hcrx_pinv);
+ dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE,
+ &pinv, sizeof(pinv));
+ dccp_insert_option(sk, skb, TFRC_OPT_RECEIVE_RATE,
+ &x_recv, sizeof(x_recv));
+}
+
+/* calculate first loss interval
+ *
+ * returns estimated loss interval in usecs */
+
+static u32 ccid3_hc_rx_calc_first_li(struct sock *sk)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
+ struct dccp_rx_hist_entry *entry, *next, *tail = NULL;
+ u32 rtt, delta, x_recv, fval, p, tmp2;
+ struct timeval tstamp = { 0, };
+ int interval = 0;
+ int win_count = 0;
+ int step = 0;
+ u64 tmp1;
+
+ list_for_each_entry_safe(entry, next, &hcrx->ccid3hcrx_hist,
+ dccphrx_node) {
+ if (dccp_rx_hist_entry_data_packet(entry)) {
+ tail = entry;
+
+ switch (step) {
+ case 0:
+ tstamp = entry->dccphrx_tstamp;
+ win_count = entry->dccphrx_ccval;
+ step = 1;
+ break;
+ case 1:
+ interval = win_count - entry->dccphrx_ccval;
+ if (interval < 0)
+ interval += TFRC_WIN_COUNT_LIMIT;
+ if (interval > 4)
+ goto found;
+ break;
+ }
+ }
+ }
+
+ if (step == 0) {
+ printk(KERN_CRIT "%s: %s, sk=%p, packet history contains no "
+ "data packets!\n",
+ __FUNCTION__, dccp_role(sk), sk);
+ return ~0;
+ }
+
+ if (interval == 0) {
+ ccid3_pr_debug("%s, sk=%p, Could not find a win_count "
+ "interval > 0. Defaulting to 1\n",
+ dccp_role(sk), sk);
+ interval = 1;
+ }
+found:
+ rtt = timeval_delta(&tstamp, &tail->dccphrx_tstamp) * 4 / interval;
+ ccid3_pr_debug("%s, sk=%p, approximated RTT to %uus\n",
+ dccp_role(sk), sk, rtt);
+ if (rtt == 0)
+ rtt = 1;
+
+ delta = timeval_now_delta(&hcrx->ccid3hcrx_tstamp_last_feedback);
+ x_recv = hcrx->ccid3hcrx_bytes_recv * USEC_PER_SEC;
+ if (likely(delta > 1))
+ x_recv /= delta;
+
+ tmp1 = (u64)x_recv * (u64)rtt;
+ do_div(tmp1,10000000);
+ tmp2 = (u32)tmp1;
+ fval = (hcrx->ccid3hcrx_s * 100000) / tmp2;
+ /* do not alter order above or you will get overflow on 32 bit */
+ p = tfrc_calc_x_reverse_lookup(fval);
+ ccid3_pr_debug("%s, sk=%p, receive rate=%u bytes/s, implied "
+ "loss rate=%u\n", dccp_role(sk), sk, x_recv, p);
+
+ if (p == 0)
+ return ~0;
+ else
+ return 1000000 / p;
+}
+
+static void ccid3_hc_rx_update_li(struct sock *sk, u64 seq_loss, u8 win_loss)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
+
+ if (seq_loss != DCCP_MAX_SEQNO + 1 &&
+ list_empty(&hcrx->ccid3hcrx_li_hist)) {
+ struct dccp_li_hist_entry *li_tail;
+
+ li_tail = dccp_li_hist_interval_new(ccid3_li_hist,
+ &hcrx->ccid3hcrx_li_hist,
+ seq_loss, win_loss);
+ if (li_tail == NULL)
+ return;
+ li_tail->dccplih_interval = ccid3_hc_rx_calc_first_li(sk);
+ }
+ /* FIXME: find end of interval */
+}
+
+static void ccid3_hc_rx_detect_loss(struct sock *sk)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
+ u8 win_loss;
+ const u64 seq_loss = dccp_rx_hist_detect_loss(&hcrx->ccid3hcrx_hist,
+ &hcrx->ccid3hcrx_li_hist,
+ &win_loss);
+
+ ccid3_hc_rx_update_li(sk, seq_loss, win_loss);
+}
+
+static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
+ const struct dccp_options_received *opt_recv;
+ struct dccp_rx_hist_entry *packet;
+ struct timeval now;
+ u8 win_count;
+ u32 p_prev;
+ int ins;
+
+ if (hcrx == NULL)
+ return;
+
+ BUG_ON(!(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA ||
+ hcrx->ccid3hcrx_state == TFRC_RSTATE_DATA));
+
+ opt_recv = &dp->dccps_options_received;
+
+ switch (DCCP_SKB_CB(skb)->dccpd_type) {
+ case DCCP_PKT_ACK:
+ if (hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)
+ return;
+ case DCCP_PKT_DATAACK:
+ if (opt_recv->dccpor_timestamp_echo == 0)
+ break;
+ p_prev = hcrx->ccid3hcrx_rtt;
+ do_gettimeofday(&now);
+ hcrx->ccid3hcrx_rtt = timeval_usecs(&now) -
+ (opt_recv->dccpor_timestamp_echo -
+ opt_recv->dccpor_elapsed_time) * 10;
+ if (p_prev != hcrx->ccid3hcrx_rtt)
+ ccid3_pr_debug("%s, New RTT=%luus, elapsed time=%u\n",
+ dccp_role(sk), hcrx->ccid3hcrx_rtt,
+ opt_recv->dccpor_elapsed_time);
+ break;
+ case DCCP_PKT_DATA:
+ break;
+ default:
+ ccid3_pr_debug("%s, sk=%p, not DATA/DATAACK/ACK packet(%s)\n",
+ dccp_role(sk), sk,
+ dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type));
+ return;
+ }
+
+ packet = dccp_rx_hist_entry_new(ccid3_rx_hist, opt_recv->dccpor_ndp,
+ skb, SLAB_ATOMIC);
+ if (packet == NULL) {
+ ccid3_pr_debug("%s, sk=%p, Not enough mem to add rx packet "
+ "to history (consider it lost)!",
+ dccp_role(sk), sk);
+ return;
+ }
+
+ win_count = packet->dccphrx_ccval;
+
+ ins = dccp_rx_hist_add_packet(ccid3_rx_hist, &hcrx->ccid3hcrx_hist,
+ &hcrx->ccid3hcrx_li_hist, packet);
+
+ if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK)
+ return;
+
+ switch (hcrx->ccid3hcrx_state) {
+ case TFRC_RSTATE_NO_DATA:
+ ccid3_pr_debug("%s, sk=%p(%s), skb=%p, sending initial "
+ "feedback\n",
+ dccp_role(sk), sk,
+ dccp_state_name(sk->sk_state), skb);
+ ccid3_hc_rx_send_feedback(sk);
+ ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA);
+ return;
+ case TFRC_RSTATE_DATA:
+ hcrx->ccid3hcrx_bytes_recv += skb->len -
+ dccp_hdr(skb)->dccph_doff * 4;
+ if (ins != 0)
+ break;
+
+ do_gettimeofday(&now);
+ if (timeval_delta(&now, &hcrx->ccid3hcrx_tstamp_last_ack) >=
+ hcrx->ccid3hcrx_rtt) {
+ hcrx->ccid3hcrx_tstamp_last_ack = now;
+ ccid3_hc_rx_send_feedback(sk);
+ }
+ return;
+ default:
+ printk(KERN_CRIT "%s: %s, sk=%p, Illegal state (%d)!\n",
+ __FUNCTION__, dccp_role(sk), sk, hcrx->ccid3hcrx_state);
+ dump_stack();
+ return;
+ }
+
+ /* Dealing with packet loss */
+ ccid3_pr_debug("%s, sk=%p(%s), data loss! Reacting...\n",
+ dccp_role(sk), sk, dccp_state_name(sk->sk_state));
+
+ ccid3_hc_rx_detect_loss(sk);
+ p_prev = hcrx->ccid3hcrx_p;
+
+ /* Calculate loss event rate */
+ if (!list_empty(&hcrx->ccid3hcrx_li_hist))
+ /* Scaling up by 1000000 as fixed decimal */
+ hcrx->ccid3hcrx_p = 1000000 / dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);
+
+ if (hcrx->ccid3hcrx_p > p_prev) {
+ ccid3_hc_rx_send_feedback(sk);
+ return;
+ }
+}
+
+static int ccid3_hc_rx_init(struct sock *sk)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid3_hc_rx_sock *hcrx;
+
+ ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
+
+ hcrx = dp->dccps_hc_rx_ccid_private = kmalloc(sizeof(*hcrx),
+ gfp_any());
+ if (hcrx == NULL)
+ return -ENOMEM;
+
+ memset(hcrx, 0, sizeof(*hcrx));
+
+ if (dp->dccps_packet_size >= TFRC_MIN_PACKET_SIZE &&
+ dp->dccps_packet_size <= TFRC_MAX_PACKET_SIZE)
+ hcrx->ccid3hcrx_s = dp->dccps_packet_size;
+ else
+ hcrx->ccid3hcrx_s = TFRC_STD_PACKET_SIZE;
+
+ hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA;
+ INIT_LIST_HEAD(&hcrx->ccid3hcrx_hist);
+ INIT_LIST_HEAD(&hcrx->ccid3hcrx_li_hist);
+ /*
+ * XXX this seems to be paranoid, need to think more about this, for
+ * now start with something different than zero. -acme
+ */
+ hcrx->ccid3hcrx_rtt = USEC_PER_SEC / 5;
+ return 0;
+}
+
+static void ccid3_hc_rx_exit(struct sock *sk)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
+
+ ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
+
+ if (hcrx == NULL)
+ return;
+
+ ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM);
+
+ /* Empty packet history */
+ dccp_rx_hist_purge(ccid3_rx_hist, &hcrx->ccid3hcrx_hist);
+
+ /* Empty loss interval history */
+ dccp_li_hist_purge(ccid3_li_hist, &hcrx->ccid3hcrx_li_hist);
+
+ kfree(dp->dccps_hc_rx_ccid_private);
+ dp->dccps_hc_rx_ccid_private = NULL;
+}
+
+static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
+{
+ const struct dccp_sock *dp = dccp_sk(sk);
+ const struct ccid3_hc_rx_sock *hcrx = dp->dccps_hc_rx_ccid_private;
+
+ if (hcrx == NULL)
+ return;
+
+ info->tcpi_ca_state = hcrx->ccid3hcrx_state;
+ info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
+ info->tcpi_rcv_rtt = hcrx->ccid3hcrx_rtt;
+}
+
+static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
+{
+ const struct dccp_sock *dp = dccp_sk(sk);
+ const struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
+
+ if (hctx == NULL)
+ return;
+
+ info->tcpi_rto = hctx->ccid3hctx_t_rto;
+ info->tcpi_rtt = hctx->ccid3hctx_rtt;
+}
+
+static struct ccid ccid3 = {
+ .ccid_id = 3,
+ .ccid_name = "ccid3",
+ .ccid_owner = THIS_MODULE,
+ .ccid_init = ccid3_init,
+ .ccid_exit = ccid3_exit,
+ .ccid_hc_tx_init = ccid3_hc_tx_init,
+ .ccid_hc_tx_exit = ccid3_hc_tx_exit,
+ .ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet,
+ .ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent,
+ .ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv,
+ .ccid_hc_tx_insert_options = ccid3_hc_tx_insert_options,
+ .ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options,
+ .ccid_hc_rx_init = ccid3_hc_rx_init,
+ .ccid_hc_rx_exit = ccid3_hc_rx_exit,
+ .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options,
+ .ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv,
+ .ccid_hc_rx_get_info = ccid3_hc_rx_get_info,
+ .ccid_hc_tx_get_info = ccid3_hc_tx_get_info,
+};
+
+module_param(ccid3_debug, int, 0444);
+MODULE_PARM_DESC(ccid3_debug, "Enable debug messages");
+
+static __init int ccid3_module_init(void)
+{
+ int rc = -ENOBUFS;
+
+ ccid3_rx_hist = dccp_rx_hist_new("ccid3");
+ if (ccid3_rx_hist == NULL)
+ goto out;
+
+ ccid3_tx_hist = dccp_tx_hist_new("ccid3");
+ if (ccid3_tx_hist == NULL)
+ goto out_free_rx;
+
+ ccid3_li_hist = dccp_li_hist_new("ccid3");
+ if (ccid3_li_hist == NULL)
+ goto out_free_tx;
+
+ rc = ccid_register(&ccid3);
+ if (rc != 0)
+ goto out_free_loss_interval_history;
+out:
+ return rc;
+
+out_free_loss_interval_history:
+ dccp_li_hist_delete(ccid3_li_hist);
+ ccid3_li_hist = NULL;
+out_free_tx:
+ dccp_tx_hist_delete(ccid3_tx_hist);
+ ccid3_tx_hist = NULL;
+out_free_rx:
+ dccp_rx_hist_delete(ccid3_rx_hist);
+ ccid3_rx_hist = NULL;
+ goto out;
+}
+module_init(ccid3_module_init);
+
+static __exit void ccid3_module_exit(void)
+{
+#ifdef CONFIG_IP_DCCP_UNLOAD_HACK
+ /*
+ * Hack to use while developing, so that we get rid of the control
+ * sock, that is what keeps a refcount on dccp.ko -acme
+ */
+ extern void dccp_ctl_sock_exit(void);
+
+ dccp_ctl_sock_exit();
+#endif
+ ccid_unregister(&ccid3);
+
+ if (ccid3_tx_hist != NULL) {
+ dccp_tx_hist_delete(ccid3_tx_hist);
+ ccid3_tx_hist = NULL;
+ }
+ if (ccid3_rx_hist != NULL) {
+ dccp_rx_hist_delete(ccid3_rx_hist);
+ ccid3_rx_hist = NULL;
+ }
+ if (ccid3_li_hist != NULL) {
+ dccp_li_hist_delete(ccid3_li_hist);
+ ccid3_li_hist = NULL;
+ }
+}
+module_exit(ccid3_module_exit);
+
+MODULE_AUTHOR("Ian McDonald <iam4@cs.waikato.ac.nz>, "
+ "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
+MODULE_DESCRIPTION("DCCP TFRC CCID3 CCID");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("net-dccp-ccid-3");
diff --git a/net/dccp/ccids/ccid3.h b/net/dccp/ccids/ccid3.h
new file mode 100644
index 00000000000..ee8cbace663
--- /dev/null
+++ b/net/dccp/ccids/ccid3.h
@@ -0,0 +1,137 @@
+/*
+ * net/dccp/ccids/ccid3.h
+ *
+ * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
+ *
+ * An implementation of the DCCP protocol
+ *
+ * This code has been developed by the University of Waikato WAND
+ * research group. For further information please see http://www.wand.net.nz/
+ * or e-mail Ian McDonald - iam4@cs.waikato.ac.nz
+ *
+ * This code also uses code from Lulea University, rereleased as GPL by its
+ * authors:
+ * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
+ *
+ * Changes to meet Linux coding standards, to make it meet latest ccid3 draft
+ * and to make it work as a loadable module in the DCCP stack written by
+ * Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
+ *
+ * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#ifndef _DCCP_CCID3_H_
+#define _DCCP_CCID3_H_
+
+#include <linux/config.h>
+#include <linux/list.h>
+#include <linux/time.h>
+#include <linux/types.h>
+
+#define TFRC_MIN_PACKET_SIZE 16
+#define TFRC_STD_PACKET_SIZE 256
+#define TFRC_MAX_PACKET_SIZE 65535
+
+/* Two seconds as per CCID3 spec */
+#define TFRC_INITIAL_TIMEOUT (2 * USEC_PER_SEC)
+
+/* In usecs - half the scheduling granularity as per RFC3448 4.6 */
+#define TFRC_OPSYS_HALF_TIME_GRAN (USEC_PER_SEC / (2 * HZ))
+
+/* In seconds */
+#define TFRC_MAX_BACK_OFF_TIME 64
+
+#define TFRC_SMALLEST_P 40
+
+enum ccid3_options {
+ TFRC_OPT_LOSS_EVENT_RATE = 192,
+ TFRC_OPT_LOSS_INTERVALS = 193,
+ TFRC_OPT_RECEIVE_RATE = 194,
+};
+
+struct ccid3_options_received {
+ u64 ccid3or_seqno:48,
+ ccid3or_loss_intervals_idx:16;
+ u16 ccid3or_loss_intervals_len;
+ u32 ccid3or_loss_event_rate;
+ u32 ccid3or_receive_rate;
+};
+
+/** struct ccid3_hc_tx_sock - CCID3 sender half connection sock
+ *
+ * @ccid3hctx_state - Sender state
+ * @ccid3hctx_x - Current sending rate
+ * @ccid3hctx_x_recv - Receive rate
+ * @ccid3hctx_x_calc - Calculated send (?) rate
+ * @ccid3hctx_s - Packet size
+ * @ccid3hctx_rtt - Estimate of current round trip time in usecs
+ * @@ccid3hctx_p - Current loss event rate (0-1) scaled by 1000000
+ * @ccid3hctx_last_win_count - Last window counter sent
+ * @ccid3hctx_t_last_win_count - Timestamp of earliest packet
+ * with last_win_count value sent
+ * @ccid3hctx_no_feedback_timer - Handle to no feedback timer
+ * @ccid3hctx_idle - FIXME
+ * @ccid3hctx_t_ld - Time last doubled during slow start
+ * @ccid3hctx_t_nom - Nominal send time of next packet
+ * @ccid3hctx_t_ipi - Interpacket (send) interval
+ * @ccid3hctx_delta - Send timer delta
+ * @ccid3hctx_hist - Packet history
+ */
+struct ccid3_hc_tx_sock {
+ u32 ccid3hctx_x;
+ u32 ccid3hctx_x_recv;
+ u32 ccid3hctx_x_calc;
+ u16 ccid3hctx_s;
+ u32 ccid3hctx_rtt;
+ u32 ccid3hctx_p;
+ u8 ccid3hctx_state;
+ u8 ccid3hctx_last_win_count;
+ u8 ccid3hctx_idle;
+ struct timeval ccid3hctx_t_last_win_count;
+ struct timer_list ccid3hctx_no_feedback_timer;
+ struct timeval ccid3hctx_t_ld;
+ struct timeval ccid3hctx_t_nom;
+ u32 ccid3hctx_t_rto;
+ u32 ccid3hctx_t_ipi;
+ u32 ccid3hctx_delta;
+ struct list_head ccid3hctx_hist;
+ struct ccid3_options_received ccid3hctx_options_received;
+};
+
+struct ccid3_hc_rx_sock {
+ u64 ccid3hcrx_seqno_last_counter:48,
+ ccid3hcrx_state:8,
+ ccid3hcrx_last_counter:4;
+ unsigned long ccid3hcrx_rtt;
+ u32 ccid3hcrx_p;
+ u32 ccid3hcrx_bytes_recv;
+ struct timeval ccid3hcrx_tstamp_last_feedback;
+ struct timeval ccid3hcrx_tstamp_last_ack;
+ struct list_head ccid3hcrx_hist;
+ struct list_head ccid3hcrx_li_hist;
+ u16 ccid3hcrx_s;
+ u32 ccid3hcrx_pinv;
+ u32 ccid3hcrx_elapsed_time;
+ u32 ccid3hcrx_x_recv;
+};
+
+#define ccid3_hc_tx_field(s,field) (s->dccps_hc_tx_ccid_private == NULL ? 0 : \
+ ((struct ccid3_hc_tx_sock *)s->dccps_hc_tx_ccid_private)->ccid3hctx_##field)
+
+#define ccid3_hc_rx_field(s,field) (s->dccps_hc_rx_ccid_private == NULL ? 0 : \
+ ((struct ccid3_hc_rx_sock *)s->dccps_hc_rx_ccid_private)->ccid3hcrx_##field)
+
+#endif /* _DCCP_CCID3_H_ */
diff --git a/net/dccp/ccids/lib/Makefile b/net/dccp/ccids/lib/Makefile
new file mode 100644
index 00000000000..5f940a6cbac
--- /dev/null
+++ b/net/dccp/ccids/lib/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_IP_DCCP_TFRC_LIB) += dccp_tfrc_lib.o
+
+dccp_tfrc_lib-y := loss_interval.o packet_history.o tfrc_equation.o
diff --git a/net/dccp/ccids/lib/loss_interval.c b/net/dccp/ccids/lib/loss_interval.c
new file mode 100644
index 00000000000..4c01a54143a
--- /dev/null
+++ b/net/dccp/ccids/lib/loss_interval.c
@@ -0,0 +1,144 @@
+/*
+ * net/dccp/ccids/lib/loss_interval.c
+ *
+ * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
+ * Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
+ * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+
+#include "loss_interval.h"
+
+struct dccp_li_hist *dccp_li_hist_new(const char *name)
+{
+ struct dccp_li_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC);
+ static const char dccp_li_hist_mask[] = "li_hist_%s";
+ char *slab_name;
+
+ if (hist == NULL)
+ goto out;
+
+ slab_name = kmalloc(strlen(name) + sizeof(dccp_li_hist_mask) - 1,
+ GFP_ATOMIC);
+ if (slab_name == NULL)
+ goto out_free_hist;
+
+ sprintf(slab_name, dccp_li_hist_mask, name);
+ hist->dccplih_slab = kmem_cache_create(slab_name,
+ sizeof(struct dccp_li_hist_entry),
+ 0, SLAB_HWCACHE_ALIGN,
+ NULL, NULL);
+ if (hist->dccplih_slab == NULL)
+ goto out_free_slab_name;
+out:
+ return hist;
+out_free_slab_name:
+ kfree(slab_name);
+out_free_hist:
+ kfree(hist);
+ hist = NULL;
+ goto out;
+}
+
+EXPORT_SYMBOL_GPL(dccp_li_hist_new);
+
+void dccp_li_hist_delete(struct dccp_li_hist *hist)
+{
+ const char* name = kmem_cache_name(hist->dccplih_slab);
+
+ kmem_cache_destroy(hist->dccplih_slab);
+ kfree(name);
+ kfree(hist);
+}
+
+EXPORT_SYMBOL_GPL(dccp_li_hist_delete);
+
+void dccp_li_hist_purge(struct dccp_li_hist *hist, struct list_head *list)
+{
+ struct dccp_li_hist_entry *entry, *next;
+
+ list_for_each_entry_safe(entry, next, list, dccplih_node) {
+ list_del_init(&entry->dccplih_node);
+ kmem_cache_free(hist->dccplih_slab, entry);
+ }
+}
+
+EXPORT_SYMBOL_GPL(dccp_li_hist_purge);
+
+/* Weights used to calculate loss event rate */
+/*
+ * These are integers as per section 8 of RFC3448. We can then divide by 4 *
+ * when we use it.
+ */
+static const int dccp_li_hist_w[DCCP_LI_HIST_IVAL_F_LENGTH] = {
+ 4, 4, 4, 4, 3, 2, 1, 1,
+};
+
+u32 dccp_li_hist_calc_i_mean(struct list_head *list)
+{
+ struct dccp_li_hist_entry *li_entry, *li_next;
+ int i = 0;
+ u32 i_tot;
+ u32 i_tot0 = 0;
+ u32 i_tot1 = 0;
+ u32 w_tot = 0;
+
+ list_for_each_entry_safe(li_entry, li_next, list, dccplih_node) {
+ if (i < DCCP_LI_HIST_IVAL_F_LENGTH) {
+ i_tot0 += li_entry->dccplih_interval * dccp_li_hist_w[i];
+ w_tot += dccp_li_hist_w[i];
+ }
+
+ if (i != 0)
+ i_tot1 += li_entry->dccplih_interval * dccp_li_hist_w[i - 1];
+
+ if (++i > DCCP_LI_HIST_IVAL_F_LENGTH)
+ break;
+ }
+
+ if (i != DCCP_LI_HIST_IVAL_F_LENGTH)
+ return 0;
+
+ i_tot = max(i_tot0, i_tot1);
+
+ /* FIXME: Why do we do this? -Ian McDonald */
+ if (i_tot * 4 < w_tot)
+ i_tot = w_tot * 4;
+
+ return i_tot * 4 / w_tot;
+}
+
+EXPORT_SYMBOL_GPL(dccp_li_hist_calc_i_mean);
+
+struct dccp_li_hist_entry *dccp_li_hist_interval_new(struct dccp_li_hist *hist,
+ struct list_head *list,
+ const u64 seq_loss,
+ const u8 win_loss)
+{
+ struct dccp_li_hist_entry *tail = NULL, *entry;
+ int i;
+
+ for (i = 0; i <= DCCP_LI_HIST_IVAL_F_LENGTH; ++i) {
+ entry = dccp_li_hist_entry_new(hist, SLAB_ATOMIC);
+ if (entry == NULL) {
+ dccp_li_hist_purge(hist, list);
+ return NULL;
+ }
+ if (tail == NULL)
+ tail = entry;
+ list_add(&entry->dccplih_node, list);
+ }
+
+ entry->dccplih_seqno = seq_loss;
+ entry->dccplih_win_count = win_loss;
+ return tail;
+}
+
+EXPORT_SYMBOL_GPL(dccp_li_hist_interval_new);
diff --git a/net/dccp/ccids/lib/loss_interval.h b/net/dccp/ccids/lib/loss_interval.h
new file mode 100644
index 00000000000..13ad47ba142
--- /dev/null
+++ b/net/dccp/ccids/lib/loss_interval.h
@@ -0,0 +1,61 @@
+#ifndef _DCCP_LI_HIST_
+#define _DCCP_LI_HIST_
+/*
+ * net/dccp/ccids/lib/loss_interval.h
+ *
+ * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
+ * Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
+ * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ */
+
+#include <linux/config.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+
+#define DCCP_LI_HIST_IVAL_F_LENGTH 8
+
+struct dccp_li_hist {
+ kmem_cache_t *dccplih_slab;
+};
+
+extern struct dccp_li_hist *dccp_li_hist_new(const char *name);
+extern void dccp_li_hist_delete(struct dccp_li_hist *hist);
+
+struct dccp_li_hist_entry {
+ struct list_head dccplih_node;
+ u64 dccplih_seqno:48,
+ dccplih_win_count:4;
+ u32 dccplih_interval;
+};
+
+static inline struct dccp_li_hist_entry *
+ dccp_li_hist_entry_new(struct dccp_li_hist *hist,
+ const unsigned int __nocast prio)
+{
+ return kmem_cache_alloc(hist->dccplih_slab, prio);
+}
+
+static inline void dccp_li_hist_entry_delete(struct dccp_li_hist *hist,
+ struct dccp_li_hist_entry *entry)
+{
+ if (entry != NULL)
+ kmem_cache_free(hist->dccplih_slab, entry);
+}
+
+extern void dccp_li_hist_purge(struct dccp_li_hist *hist,
+ struct list_head *list);
+
+extern u32 dccp_li_hist_calc_i_mean(struct list_head *list);
+
+extern struct dccp_li_hist_entry *
+ dccp_li_hist_interval_new(struct dccp_li_hist *hist,
+ struct list_head *list,
+ const u64 seq_loss,
+ const u8 win_loss);
+#endif /* _DCCP_LI_HIST_ */
diff --git a/net/dccp/ccids/lib/packet_history.c b/net/dccp/ccids/lib/packet_history.c
new file mode 100644
index 00000000000..d3f9d205383
--- /dev/null
+++ b/net/dccp/ccids/lib/packet_history.c
@@ -0,0 +1,398 @@
+/*
+ * net/dccp/packet_history.h
+ *
+ * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
+ *
+ * An implementation of the DCCP protocol
+ *
+ * This code has been developed by the University of Waikato WAND
+ * research group. For further information please see http://www.wand.net.nz/
+ * or e-mail Ian McDonald - iam4@cs.waikato.ac.nz
+ *
+ * This code also uses code from Lulea University, rereleased as GPL by its
+ * authors:
+ * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
+ *
+ * Changes to meet Linux coding standards, to make it meet latest ccid3 draft
+ * and to make it work as a loadable module in the DCCP stack written by
+ * Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
+ *
+ * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/string.h>
+
+#include "packet_history.h"
+
+struct dccp_rx_hist *dccp_rx_hist_new(const char *name)
+{
+ struct dccp_rx_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC);
+ static const char dccp_rx_hist_mask[] = "rx_hist_%s";
+ char *slab_name;
+
+ if (hist == NULL)
+ goto out;
+
+ slab_name = kmalloc(strlen(name) + sizeof(dccp_rx_hist_mask) - 1,
+ GFP_ATOMIC);
+ if (slab_name == NULL)
+ goto out_free_hist;
+
+ sprintf(slab_name, dccp_rx_hist_mask, name);
+ hist->dccprxh_slab = kmem_cache_create(slab_name,
+ sizeof(struct dccp_rx_hist_entry),
+ 0, SLAB_HWCACHE_ALIGN,
+ NULL, NULL);
+ if (hist->dccprxh_slab == NULL)
+ goto out_free_slab_name;
+out:
+ return hist;
+out_free_slab_name:
+ kfree(slab_name);
+out_free_hist:
+ kfree(hist);
+ hist = NULL;
+ goto out;
+}
+
+EXPORT_SYMBOL_GPL(dccp_rx_hist_new);
+
+void dccp_rx_hist_delete(struct dccp_rx_hist *hist)
+{
+ const char* name = kmem_cache_name(hist->dccprxh_slab);
+
+ kmem_cache_destroy(hist->dccprxh_slab);
+ kfree(name);
+ kfree(hist);
+}
+
+EXPORT_SYMBOL_GPL(dccp_rx_hist_delete);
+
+void dccp_rx_hist_purge(struct dccp_rx_hist *hist, struct list_head *list)
+{
+ struct dccp_rx_hist_entry *entry, *next;
+
+ list_for_each_entry_safe(entry, next, list, dccphrx_node) {
+ list_del_init(&entry->dccphrx_node);
+ kmem_cache_free(hist->dccprxh_slab, entry);
+ }
+}
+
+EXPORT_SYMBOL_GPL(dccp_rx_hist_purge);
+
+struct dccp_rx_hist_entry *
+ dccp_rx_hist_find_data_packet(const struct list_head *list)
+{
+ struct dccp_rx_hist_entry *entry, *packet = NULL;
+
+ list_for_each_entry(entry, list, dccphrx_node)
+ if (entry->dccphrx_type == DCCP_PKT_DATA ||
+ entry->dccphrx_type == DCCP_PKT_DATAACK) {
+ packet = entry;
+ break;
+ }
+
+ return packet;
+}
+
+EXPORT_SYMBOL_GPL(dccp_rx_hist_find_data_packet);
+
+int dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
+ struct list_head *rx_list,
+ struct list_head *li_list,
+ struct dccp_rx_hist_entry *packet)
+{
+ struct dccp_rx_hist_entry *entry, *next, *iter;
+ u8 num_later = 0;
+
+ iter = dccp_rx_hist_head(rx_list);
+ if (iter == NULL)
+ dccp_rx_hist_add_entry(rx_list, packet);
+ else {
+ const u64 seqno = packet->dccphrx_seqno;
+
+ if (after48(seqno, iter->dccphrx_seqno))
+ dccp_rx_hist_add_entry(rx_list, packet);
+ else {
+ if (dccp_rx_hist_entry_data_packet(iter))
+ num_later = 1;
+
+ list_for_each_entry_continue(iter, rx_list,
+ dccphrx_node) {
+ if (after48(seqno, iter->dccphrx_seqno)) {
+ dccp_rx_hist_add_entry(&iter->dccphrx_node,
+ packet);
+ goto trim_history;
+ }
+
+ if (dccp_rx_hist_entry_data_packet(iter))
+ num_later++;
+
+ if (num_later == TFRC_RECV_NUM_LATE_LOSS) {
+ dccp_rx_hist_entry_delete(hist, packet);
+ return 1;
+ }
+ }
+
+ if (num_later < TFRC_RECV_NUM_LATE_LOSS)
+ dccp_rx_hist_add_entry(rx_list, packet);
+ /*
+ * FIXME: else what? should we destroy the packet
+ * like above?
+ */
+ }
+ }
+
+trim_history:
+ /*
+ * Trim history (remove all packets after the NUM_LATE_LOSS + 1
+ * data packets)
+ */
+ num_later = TFRC_RECV_NUM_LATE_LOSS + 1;
+
+ if (!list_empty(li_list)) {
+ list_for_each_entry_safe(entry, next, rx_list, dccphrx_node) {
+ if (num_later == 0) {
+ list_del_init(&entry->dccphrx_node);
+ dccp_rx_hist_entry_delete(hist, entry);
+ } else if (dccp_rx_hist_entry_data_packet(entry))
+ --num_later;
+ }
+ } else {
+ int step = 0;
+ u8 win_count = 0; /* Not needed, but lets shut up gcc */
+ int tmp;
+ /*
+ * We have no loss interval history so we need at least one
+ * rtt:s of data packets to approximate rtt.
+ */
+ list_for_each_entry_safe(entry, next, rx_list, dccphrx_node) {
+ if (num_later == 0) {
+ switch (step) {
+ case 0:
+ step = 1;
+ /* OK, find next data packet */
+ num_later = 1;
+ break;
+ case 1:
+ step = 2;
+ /* OK, find next data packet */
+ num_later = 1;
+ win_count = entry->dccphrx_ccval;
+ break;
+ case 2:
+ tmp = win_count - entry->dccphrx_ccval;
+ if (tmp < 0)
+ tmp += TFRC_WIN_COUNT_LIMIT;
+ if (tmp > TFRC_WIN_COUNT_PER_RTT + 1) {
+ /*
+ * We have found a packet older
+ * than one rtt remove the rest
+ */
+ step = 3;
+ } else /* OK, find next data packet */
+ num_later = 1;
+ break;
+ case 3:
+ list_del_init(&entry->dccphrx_node);
+ dccp_rx_hist_entry_delete(hist, entry);
+ break;
+ }
+ } else if (dccp_rx_hist_entry_data_packet(entry))
+ --num_later;
+ }
+ }
+
+ return 0;
+}
+
+EXPORT_SYMBOL_GPL(dccp_rx_hist_add_packet);
+
+u64 dccp_rx_hist_detect_loss(struct list_head *rx_list,
+ struct list_head *li_list, u8 *win_loss)
+{
+ struct dccp_rx_hist_entry *entry, *next, *packet;
+ struct dccp_rx_hist_entry *a_loss = NULL;
+ struct dccp_rx_hist_entry *b_loss = NULL;
+ u64 seq_loss = DCCP_MAX_SEQNO + 1;
+ u8 num_later = TFRC_RECV_NUM_LATE_LOSS;
+
+ list_for_each_entry_safe(entry, next, rx_list, dccphrx_node) {
+ if (num_later == 0) {
+ b_loss = entry;
+ break;
+ } else if (dccp_rx_hist_entry_data_packet(entry))
+ --num_later;
+ }
+
+ if (b_loss == NULL)
+ goto out;
+
+ num_later = 1;
+ list_for_each_entry_safe_continue(entry, next, rx_list, dccphrx_node) {
+ if (num_later == 0) {
+ a_loss = entry;
+ break;
+ } else if (dccp_rx_hist_entry_data_packet(entry))
+ --num_later;
+ }
+
+ if (a_loss == NULL) {
+ if (list_empty(li_list)) {
+ /* no loss event have occured yet */
+ LIMIT_NETDEBUG("%s: TODO: find a lost data packet by "
+ "comparing to initial seqno\n",
+ __FUNCTION__);
+ goto out;
+ } else {
+ LIMIT_NETDEBUG("%s: Less than 4 data pkts in history!",
+ __FUNCTION__);
+ goto out;
+ }
+ }
+
+ /* Locate a lost data packet */
+ entry = packet = b_loss;
+ list_for_each_entry_safe_continue(entry, next, rx_list, dccphrx_node) {
+ u64 delta = dccp_delta_seqno(entry->dccphrx_seqno,
+ packet->dccphrx_seqno);
+
+ if (delta != 0) {
+ if (dccp_rx_hist_entry_data_packet(packet))
+ --delta;
+ /*
+ * FIXME: check this, probably this % usage is because
+ * in earlier drafts the ndp count was just 8 bits
+ * long, but now it cam be up to 24 bits long.
+ */
+#if 0
+ if (delta % DCCP_NDP_LIMIT !=
+ (packet->dccphrx_ndp -
+ entry->dccphrx_ndp) % DCCP_NDP_LIMIT)
+#endif
+ if (delta != packet->dccphrx_ndp - entry->dccphrx_ndp) {
+ seq_loss = entry->dccphrx_seqno;
+ dccp_inc_seqno(&seq_loss);
+ }
+ }
+ packet = entry;
+ if (packet == a_loss)
+ break;
+ }
+out:
+ if (seq_loss != DCCP_MAX_SEQNO + 1)
+ *win_loss = a_loss->dccphrx_ccval;
+ else
+ *win_loss = 0; /* Paranoia */
+
+ return seq_loss;
+}
+
+EXPORT_SYMBOL_GPL(dccp_rx_hist_detect_loss);
+
+struct dccp_tx_hist *dccp_tx_hist_new(const char *name)
+{
+ struct dccp_tx_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC);
+ static const char dccp_tx_hist_mask[] = "tx_hist_%s";
+ char *slab_name;
+
+ if (hist == NULL)
+ goto out;
+
+ slab_name = kmalloc(strlen(name) + sizeof(dccp_tx_hist_mask) - 1,
+ GFP_ATOMIC);
+ if (slab_name == NULL)
+ goto out_free_hist;
+
+ sprintf(slab_name, dccp_tx_hist_mask, name);
+ hist->dccptxh_slab = kmem_cache_create(slab_name,
+ sizeof(struct dccp_tx_hist_entry),
+ 0, SLAB_HWCACHE_ALIGN,
+ NULL, NULL);
+ if (hist->dccptxh_slab == NULL)
+ goto out_free_slab_name;
+out:
+ return hist;
+out_free_slab_name:
+ kfree(slab_name);
+out_free_hist:
+ kfree(hist);
+ hist = NULL;
+ goto out;
+}
+
+EXPORT_SYMBOL_GPL(dccp_tx_hist_new);
+
+void dccp_tx_hist_delete(struct dccp_tx_hist *hist)
+{
+ const char* name = kmem_cache_name(hist->dccptxh_slab);
+
+ kmem_cache_destroy(hist->dccptxh_slab);
+ kfree(name);
+ kfree(hist);
+}
+
+EXPORT_SYMBOL_GPL(dccp_tx_hist_delete);
+
+struct dccp_tx_hist_entry *
+ dccp_tx_hist_find_entry(const struct list_head *list, const u64 seq)
+{
+ struct dccp_tx_hist_entry *packet = NULL, *entry;
+
+ list_for_each_entry(entry, list, dccphtx_node)
+ if (entry->dccphtx_seqno == seq) {
+ packet = entry;
+ break;
+ }
+
+ return packet;
+}
+
+EXPORT_SYMBOL_GPL(dccp_tx_hist_find_entry);
+
+void dccp_tx_hist_purge_older(struct dccp_tx_hist *hist,
+ struct list_head *list,
+ struct dccp_tx_hist_entry *packet)
+{
+ struct dccp_tx_hist_entry *next;
+
+ list_for_each_entry_safe_continue(packet, next, list, dccphtx_node) {
+ list_del_init(&packet->dccphtx_node);
+ dccp_tx_hist_entry_delete(hist, packet);
+ }
+}
+
+EXPORT_SYMBOL_GPL(dccp_tx_hist_purge_older);
+
+void dccp_tx_hist_purge(struct dccp_tx_hist *hist, struct list_head *list)
+{
+ struct dccp_tx_hist_entry *entry, *next;
+
+ list_for_each_entry_safe(entry, next, list, dccphtx_node) {
+ list_del_init(&entry->dccphtx_node);
+ dccp_tx_hist_entry_delete(hist, entry);
+ }
+}
+
+EXPORT_SYMBOL_GPL(dccp_tx_hist_purge);
+
+MODULE_AUTHOR("Ian McDonald <iam4@cs.waikato.ac.nz>, "
+ "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
+MODULE_DESCRIPTION("DCCP TFRC library");
+MODULE_LICENSE("GPL");
diff --git a/net/dccp/ccids/lib/packet_history.h b/net/dccp/ccids/lib/packet_history.h
new file mode 100644
index 00000000000..fb90a91aa93
--- /dev/null
+++ b/net/dccp/ccids/lib/packet_history.h
@@ -0,0 +1,199 @@
+/*
+ * net/dccp/packet_history.h
+ *
+ * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
+ *
+ * An implementation of the DCCP protocol
+ *
+ * This code has been developed by the University of Waikato WAND
+ * research group. For further information please see http://www.wand.net.nz/
+ * or e-mail Ian McDonald - iam4@cs.waikato.ac.nz
+ *
+ * This code also uses code from Lulea University, rereleased as GPL by its
+ * authors:
+ * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
+ *
+ * Changes to meet Linux coding standards, to make it meet latest ccid3 draft
+ * and to make it work as a loadable module in the DCCP stack written by
+ * Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
+ *
+ * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef _DCCP_PKT_HIST_
+#define _DCCP_PKT_HIST_
+
+#include <linux/config.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+
+#include "../../dccp.h"
+
+/* Number of later packets received before one is considered lost */
+#define TFRC_RECV_NUM_LATE_LOSS 3
+
+#define TFRC_WIN_COUNT_PER_RTT 4
+#define TFRC_WIN_COUNT_LIMIT 16
+
+struct dccp_tx_hist_entry {
+ struct list_head dccphtx_node;
+ u64 dccphtx_seqno:48,
+ dccphtx_ccval:4,
+ dccphtx_sent:1;
+ u32 dccphtx_rtt;
+ struct timeval dccphtx_tstamp;
+};
+
+struct dccp_rx_hist_entry {
+ struct list_head dccphrx_node;
+ u64 dccphrx_seqno:48,
+ dccphrx_ccval:4,
+ dccphrx_type:4;
+ u32 dccphrx_ndp; /* In fact it is from 8 to 24 bits */
+ struct timeval dccphrx_tstamp;
+};
+
+struct dccp_tx_hist {
+ kmem_cache_t *dccptxh_slab;
+};
+
+extern struct dccp_tx_hist *dccp_tx_hist_new(const char *name);
+extern void dccp_tx_hist_delete(struct dccp_tx_hist *hist);
+
+struct dccp_rx_hist {
+ kmem_cache_t *dccprxh_slab;
+};
+
+extern struct dccp_rx_hist *dccp_rx_hist_new(const char *name);
+extern void dccp_rx_hist_delete(struct dccp_rx_hist *hist);
+extern struct dccp_rx_hist_entry *
+ dccp_rx_hist_find_data_packet(const struct list_head *list);
+
+static inline struct dccp_tx_hist_entry *
+ dccp_tx_hist_entry_new(struct dccp_tx_hist *hist,
+ const unsigned int __nocast prio)
+{
+ struct dccp_tx_hist_entry *entry = kmem_cache_alloc(hist->dccptxh_slab,
+ prio);
+
+ if (entry != NULL)
+ entry->dccphtx_sent = 0;
+
+ return entry;
+}
+
+static inline void dccp_tx_hist_entry_delete(struct dccp_tx_hist *hist,
+ struct dccp_tx_hist_entry *entry)
+{
+ if (entry != NULL)
+ kmem_cache_free(hist->dccptxh_slab, entry);
+}
+
+extern struct dccp_tx_hist_entry *
+ dccp_tx_hist_find_entry(const struct list_head *list,
+ const u64 seq);
+
+static inline void dccp_tx_hist_add_entry(struct list_head *list,
+ struct dccp_tx_hist_entry *entry)
+{
+ list_add(&entry->dccphtx_node, list);
+}
+
+extern void dccp_tx_hist_purge_older(struct dccp_tx_hist *hist,
+ struct list_head *list,
+ struct dccp_tx_hist_entry *next);
+
+extern void dccp_tx_hist_purge(struct dccp_tx_hist *hist,
+ struct list_head *list);
+
+static inline struct dccp_tx_hist_entry *
+ dccp_tx_hist_head(struct list_head *list)
+{
+ struct dccp_tx_hist_entry *head = NULL;
+
+ if (!list_empty(list))
+ head = list_entry(list->next, struct dccp_tx_hist_entry,
+ dccphtx_node);
+ return head;
+}
+
+static inline struct dccp_rx_hist_entry *
+ dccp_rx_hist_entry_new(struct dccp_rx_hist *hist,
+ const u32 ndp,
+ const struct sk_buff *skb,
+ const unsigned int __nocast prio)
+{
+ struct dccp_rx_hist_entry *entry = kmem_cache_alloc(hist->dccprxh_slab,
+ prio);
+
+ if (entry != NULL) {
+ const struct dccp_hdr *dh = dccp_hdr(skb);
+
+ entry->dccphrx_seqno = DCCP_SKB_CB(skb)->dccpd_seq;
+ entry->dccphrx_ccval = dh->dccph_ccval;
+ entry->dccphrx_type = dh->dccph_type;
+ entry->dccphrx_ndp = ndp;
+ do_gettimeofday(&(entry->dccphrx_tstamp));
+ }
+
+ return entry;
+}
+
+static inline void dccp_rx_hist_entry_delete(struct dccp_rx_hist *hist,
+ struct dccp_rx_hist_entry *entry)
+{
+ if (entry != NULL)
+ kmem_cache_free(hist->dccprxh_slab, entry);
+}
+
+extern void dccp_rx_hist_purge(struct dccp_rx_hist *hist,
+ struct list_head *list);
+
+static inline void dccp_rx_hist_add_entry(struct list_head *list,
+ struct dccp_rx_hist_entry *entry)
+{
+ list_add(&entry->dccphrx_node, list);
+}
+
+static inline struct dccp_rx_hist_entry *
+ dccp_rx_hist_head(struct list_head *list)
+{
+ struct dccp_rx_hist_entry *head = NULL;
+
+ if (!list_empty(list))
+ head = list_entry(list->next, struct dccp_rx_hist_entry,
+ dccphrx_node);
+ return head;
+}
+
+static inline int
+ dccp_rx_hist_entry_data_packet(const struct dccp_rx_hist_entry *entry)
+{
+ return entry->dccphrx_type == DCCP_PKT_DATA ||
+ entry->dccphrx_type == DCCP_PKT_DATAACK;
+}
+
+extern int dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
+ struct list_head *rx_list,
+ struct list_head *li_list,
+ struct dccp_rx_hist_entry *packet);
+
+extern u64 dccp_rx_hist_detect_loss(struct list_head *rx_list,
+ struct list_head *li_list, u8 *win_loss);
+
+#endif /* _DCCP_PKT_HIST_ */
diff --git a/net/dccp/ccids/lib/tfrc.h b/net/dccp/ccids/lib/tfrc.h
new file mode 100644
index 00000000000..130c4c40cfe
--- /dev/null
+++ b/net/dccp/ccids/lib/tfrc.h
@@ -0,0 +1,22 @@
+#ifndef _TFRC_H_
+#define _TFRC_H_
+/*
+ * net/dccp/ccids/lib/tfrc.h
+ *
+ * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
+ * Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
+ * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/types.h>
+
+extern u32 tfrc_calc_x(u16 s, u32 R, u32 p);
+extern u32 tfrc_calc_x_reverse_lookup(u32 fvalue);
+
+#endif /* _TFRC_H_ */
diff --git a/net/dccp/ccids/lib/tfrc_equation.c b/net/dccp/ccids/lib/tfrc_equation.c
new file mode 100644
index 00000000000..d2b5933b451
--- /dev/null
+++ b/net/dccp/ccids/lib/tfrc_equation.c
@@ -0,0 +1,644 @@
+/*
+ * net/dccp/ccids/lib/tfrc_equation.c
+ *
+ * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
+ * Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
+ * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+
+#include <asm/bug.h>
+#include <asm/div64.h>
+
+#include "tfrc.h"
+
+#define TFRC_CALC_X_ARRSIZE 500
+
+#define TFRC_CALC_X_SPLIT 50000
+/* equivalent to 0.05 */
+
+static const u32 tfrc_calc_x_lookup[TFRC_CALC_X_ARRSIZE][2] = {
+ { 37172, 8172 },
+ { 53499, 11567 },
+ { 66664, 14180 },
+ { 78298, 16388 },
+ { 89021, 18339 },
+ { 99147, 20108 },
+ { 108858, 21738 },
+ { 118273, 23260 },
+ { 127474, 24693 },
+ { 136520, 26052 },
+ { 145456, 27348 },
+ { 154316, 28589 },
+ { 163130, 29783 },
+ { 171919, 30935 },
+ { 180704, 32049 },
+ { 189502, 33130 },
+ { 198328, 34180 },
+ { 207194, 35202 },
+ { 216114, 36198 },
+ { 225097, 37172 },
+ { 234153, 38123 },
+ { 243294, 39055 },
+ { 252527, 39968 },
+ { 261861, 40864 },
+ { 271305, 41743 },
+ { 280866, 42607 },
+ { 290553, 43457 },
+ { 300372, 44293 },
+ { 310333, 45117 },
+ { 320441, 45929 },
+ { 330705, 46729 },
+ { 341131, 47518 },
+ { 351728, 48297 },
+ { 362501, 49066 },
+ { 373460, 49826 },
+ { 384609, 50577 },
+ { 395958, 51320 },
+ { 407513, 52054 },
+ { 419281, 52780 },
+ { 431270, 53499 },
+ { 443487, 54211 },
+ { 455940, 54916 },
+ { 468635, 55614 },
+ { 481581, 56306 },
+ { 494785, 56991 },
+ { 508254, 57671 },
+ { 521996, 58345 },
+ { 536019, 59014 },
+ { 550331, 59677 },
+ { 564939, 60335 },
+ { 579851, 60988 },
+ { 595075, 61636 },
+ { 610619, 62279 },
+ { 626491, 62918 },
+ { 642700, 63553 },
+ { 659253, 64183 },
+ { 676158, 64809 },
+ { 693424, 65431 },
+ { 711060, 66050 },
+ { 729073, 66664 },
+ { 747472, 67275 },
+ { 766266, 67882 },
+ { 785464, 68486 },
+ { 805073, 69087 },
+ { 825103, 69684 },
+ { 845562, 70278 },
+ { 866460, 70868 },
+ { 887805, 71456 },
+ { 909606, 72041 },
+ { 931873, 72623 },
+ { 954614, 73202 },
+ { 977839, 73778 },
+ { 1001557, 74352 },
+ { 1025777, 74923 },
+ { 1050508, 75492 },
+ { 1075761, 76058 },
+ { 1101544, 76621 },
+ { 1127867, 77183 },
+ { 1154739, 77741 },
+ { 1182172, 78298 },
+ { 1210173, 78852 },
+ { 1238753, 79405 },
+ { 1267922, 79955 },
+ { 1297689, 80503 },
+ { 1328066, 81049 },
+ { 1359060, 81593 },
+ { 1390684, 82135 },
+ { 1422947, 82675 },
+ { 1455859, 83213 },
+ { 1489430, 83750 },
+ { 1523671, 84284 },
+ { 1558593, 84817 },
+ { 1594205, 85348 },
+ { 1630518, 85878 },
+ { 1667543, 86406 },
+ { 1705290, 86932 },
+ { 1743770, 87457 },
+ { 1782994, 87980 },
+ { 1822973, 88501 },
+ { 1863717, 89021 },
+ { 1905237, 89540 },
+ { 1947545, 90057 },
+ { 1990650, 90573 },
+ { 2034566, 91087 },
+ { 2079301, 91600 },
+ { 2124869, 92111 },
+ { 2171279, 92622 },
+ { 2218543, 93131 },
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+};
+
+/* Calculate the send rate as per section 3.1 of RFC3448
+
+Returns send rate in bytes per second
+
+Integer maths and lookups are used as not allowed floating point in kernel
+
+The function for Xcalc as per section 3.1 of RFC3448 is:
+
+X = s
+ -------------------------------------------------------------
+ R*sqrt(2*b*p/3) + (t_RTO * (3*sqrt(3*b*p/8) * p * (1+32*p^2)))
+
+where
+X is the trasmit rate in bytes/second
+s is the packet size in bytes
+R is the round trip time in seconds
+p is the loss event rate, between 0 and 1.0, of the number of loss events
+ as a fraction of the number of packets transmitted
+t_RTO is the TCP retransmission timeout value in seconds
+b is the number of packets acknowledged by a single TCP acknowledgement
+
+we can assume that b = 1 and t_RTO is 4 * R. With this the equation becomes:
+
+X = s
+ -----------------------------------------------------------------------
+ R * sqrt(2 * p / 3) + (12 * R * (sqrt(3 * p / 8) * p * (1 + 32 * p^2)))
+
+
+which we can break down into:
+
+X = s
+ --------
+ R * f(p)
+
+where f(p) = sqrt(2 * p / 3) + (12 * sqrt(3 * p / 8) * p * (1 + 32 * p * p))
+
+Function parameters:
+s - bytes
+R - RTT in usecs
+p - loss rate (decimal fraction multiplied by 1,000,000)
+
+Returns Xcalc in bytes per second
+
+DON'T alter this code unless you run test cases against it as the code
+has been manipulated to stop underflow/overlow.
+
+*/
+u32 tfrc_calc_x(u16 s, u32 R, u32 p)
+{
+ int index;
+ u32 f;
+ u64 tmp1, tmp2;
+
+ if (p < TFRC_CALC_X_SPLIT)
+ index = (p / (TFRC_CALC_X_SPLIT / TFRC_CALC_X_ARRSIZE)) - 1;
+ else
+ index = (p / (1000000 / TFRC_CALC_X_ARRSIZE)) - 1;
+
+ if (index < 0)
+ /* p should be 0 unless there is a bug in my code */
+ index = 0;
+
+ if (R == 0)
+ R = 1; /* RTT can't be zero or else divide by zero */
+
+ BUG_ON(index >= TFRC_CALC_X_ARRSIZE);
+
+ if (p >= TFRC_CALC_X_SPLIT)
+ f = tfrc_calc_x_lookup[index][0];
+ else
+ f = tfrc_calc_x_lookup[index][1];
+
+ tmp1 = ((u64)s * 100000000);
+ tmp2 = ((u64)R * (u64)f);
+ do_div(tmp2, 10000);
+ do_div(tmp1, tmp2);
+ /* Don't alter above math unless you test due to overflow on 32 bit */
+
+ return (u32)tmp1;
+}
+
+EXPORT_SYMBOL_GPL(tfrc_calc_x);
+
+/*
+ * args: fvalue - function value to match
+ * returns: p closest to that value
+ *
+ * both fvalue and p are multiplied by 1,000,000 to use ints
+ */
+u32 tfrc_calc_x_reverse_lookup(u32 fvalue)
+{
+ int ctr = 0;
+ int small;
+
+ if (fvalue < tfrc_calc_x_lookup[0][1])
+ return 0;
+
+ if (fvalue <= tfrc_calc_x_lookup[TFRC_CALC_X_ARRSIZE - 1][1])
+ small = 1;
+ else if (fvalue > tfrc_calc_x_lookup[TFRC_CALC_X_ARRSIZE - 1][0])
+ return 1000000;
+ else
+ small = 0;
+
+ while (fvalue > tfrc_calc_x_lookup[ctr][small])
+ ctr++;
+
+ if (small)
+ return TFRC_CALC_X_SPLIT * ctr / TFRC_CALC_X_ARRSIZE;
+ else
+ return 1000000 * ctr / TFRC_CALC_X_ARRSIZE;
+}
+
+EXPORT_SYMBOL_GPL(tfrc_calc_x_reverse_lookup);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-22 15:29:40 +0000